Cognitive Stress Reduces the Effect of Levodopa on Parkinson's Resting Tremor

Introducing the Parkinson's KinetiGraph into Routine Parkinson's Disease Care: A 3-Year Single Centre Experience

In an effort to provide timely clinical input for people with Parkinson's disease (PD) in the face of increasing demand and resource limitation in our UK based service, we introduced remote management in place of clinic appointment, including the use of the Parkinson's KinetiGraph (PKG™), a wrist-worn device that provides a continuous measure of movement. We evaluated our reporting methods and findings, the nature of unmet need we identified, our treatment recommendations and the degree of their implementation in our patients whose feedback guided our service developments. Our evaluation highlighted opportunities and challenges associated with incorporating digital data into care traditionally delivered via in-person contact.

Impact of Coronavirus Disease 2019 Pandemic on Parkinson's Disease: A Cross-Sectional Survey of 568 Spanish Patients

Background

The aim of this study was to know the impact of the coronavirus disease 2019 (COVID‐19) pandemic on Spanish patients with Parkinson's disease (PD).

Methods

This is a descriptive, observational, cross‐sectional study. An anonymous online survey with 95 questions was distributed among patients. Responses were collected from 11 May 2020 to 20 July 2020.

Results

Of a total of 570 questionnaires received, 568 (99.6%) were considered valid for the analysis (mean age, 63.5 ± 12.5 years; 53% females). A total of 553 patients (97.4%) were aware of the COVID‐19 pandemic and 68.8% were concerned about it; 95.6% took preventive measures. A total of 484 patients (85.2%) had no contact with cases of COVID‐19, and only 15 (2.6%) had confirmed COVID‐19. Although up to 72.7% remained active during confinement, 65.7% perceived a worsening of their symptoms.

Conclusions

Spanish patients with PD perceived the COVID‐19 pandemic with concern and responsibility. More than half experienced worsening of their symptoms during confinement. © 2020 International Parkinson and Movement Disorder Society

The Impact of COVID-19 on Access to Parkinson's Disease Medication

BACKGROUND

Many countries have implemented drastic measures to fight the COVID-19 pandemic. Restrictions and diversion of resources may have negatively affected patients with Parkinson's disease (PD). Our aim was to examine whether COVID-19 had an impact on access to PD medication by region and income.

METHODS

This study was conducted as part of a survey sent to members of the Movement Disorders Society focusing on access to PD medication globally.

RESULTS

Of 346 responses, 157 (45.4%) agreed that COVID-19 had affected access to PD medication, while 189 (54.6%) disagreed. 22.8% of high-income and 88.9% of low-income countries' respondents agreed that access to PD medication was affected by COVID-19. 59% of all 'yes' respondents reported increased disability of patients as an impact.

CONCLUSIONS

Access to PD medication is likely to have been affected by COVID-19 and result in deterioration of patients' symptomatic control. Resource-poor countries appear to be disproportionately affected compared to more affluent countries. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Update on neurological manifestations of COVID-19

Novel coronavirus (severe acute respiratory syndrome coronavirus-2: SARS-CoV-2) has a high homology with other cousin of coronaviruses such as SARS and Middle East respiratory syndrome-related coronavirus (MERS). After outbreak of the SARS-CoV-2 in China, it has spread so fast around the world. The main complication of coronavirus disease 2019 (COVID-19) is respiratory failure, but several patients have also been admitted to the hospital with neurological symptoms. Direct invasion, hematogenic rout, retrograde and anterograde transport along peripheral nerves are considered as main neuroinvasion mechanisms of SARS-CoV-2. In the present study, we describe the possible routes for entering of SARS-CoV-2 into the nervous system. Then, the neurological manifestations of the SARS-CoV-2 infection in the central nervous system (CNS) and peripheral nervous system (PNS) are reviewed. Furthermore, the neuropathology of the virus and its impacts on other neurological disorders are discussed.

An Overview of Acoustic-Based Interventions to Improve Motor Symptoms in Parkinson's Disease

Parkinson’s disease (PD) is characterized by motor and cognitive deficits that negatively impact on activities of daily living. While dopaminergic medications are used to attenuate motor symptoms, adjuvant therapies such as acoustic-based non-pharmacological interventions are used as a complement to standard drug treatments. At present, preliminary studies of acoustic-based interventions such as rhythmic-auditory stimulation (RAS) and vibroacoustic therapy (VAT) suggest two competing hypotheses: (1) RAS may recruit alternative motor networks that may bypass faulty spatiotemporal motor networks of movement in PD; or (2) the use of RAS enhances BG function through entrainment of beta oscillatory activities. In this mini review article, we discuss the mechanisms underlying the role of acoustic-based interventions and how it may serve to improve motor deficits such as gait impairments and tremors. We further provide suggestions for future work that may use a combination of RAS, VAT, and physical therapy to improve motor function in PD.

Potential impact and challenges associated with Parkinson's disease patient care amidst the COVID-19 global pandemic

BACKGROUND

COVID-19 has made itself known to health care providers and families across the world in a matter of months. While primarily a respiratory disorder, it has also been shown to cause neurological symptoms, which can be a concern for Parkinson's disease (PD) patients. Although PD is not as common as other conditions such as cardiovascular diseases, it affects millions of patients around the world whose care has been affected by the global pandemic.

OBJECTIVES

The aim of this review is to provide insight into the direct and indirect associations between COVID-19 and PD patient care.

RESULTS

Potential direct effects of COVID-19 include possible neurodegeneration, concerns of symptom self-management with over-the-counter (OTC) products and ICU challenges that can arise in PD patients. In addition, a subset of PD patients may be at higher risk of severe COVID-19 infection. The indirect effects of the pandemic are associated with the social distancing measures and disruptions in health care systems and PD clinical trials, which may negatively affect PD patients' mental wellbeing and create barriers in controlling their PD symptoms. On a more positive note, telemedical care is quickly emerging as a primary communication tool for virtual patient care. However, further research should be conducted to examine the applicability of telemedicine across the entire PD population, such as those with more severe symptoms living in less developed areas. With all the uncertainty during this time, it is hopeful to hear many promising COVID-19 treatments being researched, one of them being a PD drug therapy, amantadine.

CONCLUSION

Hopefully, we can consider this pandemic an opportunity to strengthen the PD community and learn more about the impact of the SARS-COV-2 virus. This review provides an overview of the interaction between COVID-19 and PD patients and future investigational retrospective studies are suggested to validate the observations.

Dopamine-responsive and dopamine-resistant resting tremor in Parkinson disease

OBJECTIVE

We tested the hypothesis that there are 2 distinct phenotypes of Parkinson tremor, based on interindividual differences in the response of resting tremor to dopaminergic medication. We also investigated whether this pattern is specific to tremor by comparing interindividual differences in the dopamine response of tremor to that of bradykinesia.

METHODS

In this exploratory study, we performed a levodopa challenge in 76 tremulous patients with Parkinson tremor. Clinical scores (Movement Disorders Society-sponsored version of the Unified Parkinson's Disease Rating Scale part III) were collected "off" and "on" a standardized dopaminergic challenge (200/50 mg dispersible levodopa-benserazide). In both sessions, resting tremor intensity was quantified using accelerometry, both during rest and during cognitive coactivation. Bradykinesia was quantified using a speeded keyboard test. We calculated the distribution of dopamine-responsiveness for resting tremor and bradykinesia. In 41 patients, a double-blinded, placebo-controlled dopaminergic challenge was repeated after approximately 6 months.

RESULTS

The dopamine response of resting tremor, but not bradykinesia, significantly departed from a normal distribution. A cluster analysis on 3 clinical and electrophysiologic markers of tremor dopamine-responsiveness revealed 3 clusters: dopamine-responsive, intermediate, and dopamine-resistant tremor. A repeated levodopa challenge after 6 months confirmed this classification. Patients with dopamine-responsive tremor had greater disease severity and tended to have a higher prevalence of dyskinesia.

CONCLUSION

Parkinson resting tremor can be divided into 3 partially overlapping phenotypes, based on the dopamine response. These tremor phenotypes may be associated with different underlying pathophysiologic mechanisms, requiring a different therapeutic approach.

COVID-19: An Early Review of Its Global Impact and Considerations for Parkinson's Disease Patient Care

While many infectious disorders are unknown to most neurologists, COVID-19 is very different. It has impacted neurologists and other health care workers, not only in our professional lives but also through the fear and panic within our own families, colleagues, patients and their families, and even in the wider public. COVID-19 affects all sorts of individuals, but the elderly with underlying chronic conditions are particularly at risk of severe disease, or even death. Parkinson's disease (PD) shares a common profile as an age-dependent degenerative disorder, frequently associated with comorbidities, particularly cardiovascular diseases, so PD patients will almost certainly fall into the high-risk group. Therefore, the aim of this review is to explore the risk of COVID-19 in PD based on the susceptibility to severe disease, its impact on PD disease severity, potential long-term sequelae, and difficulties of PD management during this outbreak, where neurologists face various challenges on how we can maintain effective care for PD patients without exposing them, or ourselves, to the risk of infection. It is less than six months since the identification of the original COVID-19 case on New Year's Eve 2019, so it is still too early to fully understand the natural history of COVID-19 and the evidence on COVID-19-related PD is scant. Though the possibilities presented are speculative, they are theory-based, and supported by prior evidence from other neurotrophic viruses closely related to SARS-CoV-2. Neurologists should be on high alert and vigilant for potential acute and chronic complications when encountering PD patients who are suspected of having COVID-19.

Cognitive load amplifies Parkinson’s tremor through excitatory network influences onto the thalamus

Parkinson’s tremor is related to cerebral activity in both the basal ganglia and a cerebello-thalamo-cortical circuit. It is a common clinical observation that tremor markedly increases during cognitive load (such as mental arithmetic), leading to serious disability. Previous research has shown that this tremor amplification is associated with reduced efficacy of dopaminergic treatment. Understanding the mechanisms of tremor amplification and its relation to catecholamines might help to better control this symptom with a targeted therapy. We reasoned that, during cognitive load, tremor amplification might result from modulatory influences onto the cerebello-thalamo-cortical circuit controlling tremor amplitude, from the ascending arousal system (bottom-up), a cognitive control network (top-down), or their combination. We have tested these hypotheses by measuring concurrent EMG and functional MRI in 33 patients with tremulous Parkinson’s disease, OFF medication, during alternating periods of rest and cognitive load (mental arithmetic). Simultaneous heart rate and pupil diameter recordings indexed activity of the arousal system (which includes noradrenergic afferences). As expected, tremor amplitude correlated with activity in a cerebello-thalamo-cortical circuit; and cognitive load increased tremor amplitude, pupil diameter, heart rate, and cerebral activity in a cognitive control network distributed over fronto-parietal cortex, insula, thalamus and anterior cingulate cortex. The novel finding, obtained through network analyses, indicates that cognitive load influences tremor by increasing activity in the cerebello-thalamo-cortical circuit in two different ways: by stimulating thalamic activity, likely through the ascending arousal system (given that this modulation correlated with changes in pupil diameter), and by strengthening connectivity between the cognitive control network and the cerebello-thalamo-cortical circuit. We conclude that both the bottom-up arousal system and a top-down cognitive control network amplify tremor when a Parkinson’s patient experiences cognitive load. Interventions aimed at attenuating noradrenergic activity or cognitive demands may help to reduce Parkinson’s tremor.

The Challenge of Managing Parkinson's Disease Patients during the COVID-19 Pandemic

The 2019 novel coronavirus (nCoV) pandemic is rapidly developing across the globe and new information is emerging expeditiously and constantly, particularly in relation to neurological illnesses. Both central and peripheral nervous system involvement has been reported including headache, dizziness, hyposmia/anosmia, taste disturbances, seizures, stroke, alteration of the sensorium, and even acute hemorrhagic necrotizing leukoencephalopathy. Varying degrees of olfactory disturbances may pre-empt the diagnosis of COVID-19. Although no direct effect of 2019 nCoV has been reported yet on Parkinson's disease, there are enormous possible indirect effects and implications. We examine the potential effects and challenges posed by this pandemic to individuals with Parkinson's disease, particularly in the Indian context where telecommunication access or support group access may be lacking for these patients. Additionally, lockdown and social distancing may pose hurdles in the provision of optimum medical therapy, particularly if patients experience motor and non-motor deteriorations due to diverse reasons.

Cerebral differences between dopamine-resistant and dopamine-responsive Parkinson’s tremor

Resting tremor in Parkinson’s disease does not always respond to dopaminergic medication. Dirkx et al. report that dopamine-resistant tremor may be the result of increased cerebellar and reduced somatosensory influences on the cerebellar thalamus, making this key node of the tremor circuit less susceptible to the inhibitory effects of dopamine.

Re-emergent tremor provocation

INTRODUCTION

Rest and re-emergent tremor (RET) in Parkinson's disease (PD) are known to be markedly variable. The aim of this study is to evaluate the effect of tremor provocation on RET latency and variability.

METHODS

We performed a prospective observational study in 21 PD patients with RET. Evaluations were conducted by accelerometric analysis of hand movements with and without provocation by counting out loud backwards from 100, in the OFF state. Differences in RET pause duration, tremor power at peak frequency, root mean square (RMS) and slope of return of the tremor after the pause was measured. Inter- and intra-subject variability were also calculated.

RESULTS

RET pause duration showed a 75% decrease after provocation (p < 0.001), which led to zero in 52% of cases, as compared to 9% in unprovoked measurements (p < 0.001). Provocation also led to a 2.57 time increase in tremor power (p < 0.001), 1.37 time increase in RMS (p < 0.001) and 2.47 time increase in slope (p < 0.001). A significant decrease in inter-subject variability was also observed (p = 0.001).

CONCLUSION

Tremor provocation led to RET amplitude increase, pause shortening, and variability decrease. Therefore, while provocation can be recommended for the evaluation of rest tremor in clinical practice, it might well annul its value for identifying the pause prior to re-emergent tremor.

The influence of posture duration on hand tremor during tasks with attention-distraction in persons with Parkinson's disease

BACKGROUND

Tremor is one of the hallmarks and most bothersome symptoms in Parkinson's disease (PD). The classical PD tremor is present at rest, but postural tremor also occurs. PD tremor can be continuous or intermittently present and can have a re-emergent nature. The tremor intensity is affected by attention and stress level. Observations of PD tremor have indicated increased tremor intensity with time during 30-s tremor assessments. This phenomenon has not previously been studied systematically. Thus, in order to contribute to our understanding of the mechanisms associated with PD tremor, our aim was to investigate the influence of time during a posture holding and a resting task on hand tremor characteristics in persons with PD compared to healthy peers.

METHOD

Fifty persons with PD and at least one tremoring hand (tremor intensity exceeding mean + 2SD of a healthy reference group (REF), N = 40) were included from a clinical trial population. Hand accelerations in a rest and postural condition were measured in 30-s assessments while the participants performed a self-paced simple subtraction task with eyes closed to standardize attention without inducing stress. Tremor intensity, maximal power, frequency of maximal power and tremor onset time was calculated for three consecutive 10-s time intervals.

RESULTS

Tremor intensity and maximal power increased significantly during the 30-s recording in the PD-group in both conditions (1st-3rd time-interval, tremor intensity: rest + 65% p < 0.0001, postural + 55% p < 0.0001; maximal power: rest + 93% p < 0.0001, postural + 82% p < 0.001). No effect of time was found on frequency of maximal power in the PD-group or on any effect measure in the REF-group.

CONCLUSION

Tremor intensity and maximal power increased with time in the PD-group during 30-s tasks, while no change with time was found in the REF-group. In contrast, frequency of maximal power remained unchanged, which may suggest that the same neural circuits were responsible for the tremor generation throughout the tasks. The increase in tremor intensity and maximal power could not solely be explained by re-emergence of tremor. This suggests an increasing or gradually more synchronized cortico-spinal drive throughout the tasks. However, this requires further studies to determine.

The effect of 8 weeks of treatment with transcranial pulsed electromagnetic fields on hand tremor and inter-hand coherence in persons with Parkinson's disease

BACKGROUND

Parkinson's disease (PD) tremor comprises asymmetric rest and postural tremor with unilateral onset. Tremor intensity can be amplified by stress and reduced by attention, and the medical treatment is complex. Mirror movements and unintentional synchronization of bimanual movements, possibly caused by insufficient inhibition of inter-hemispheric crosstalk, have been reported in PD, indicating a lag of lateralization. Potential neuroprotective effects of pulsed electromagnetic fields (PEMF) have been reported in-vitro and in rodents, as have influences of PEMF on human tremor. The aim was to investigate the effect of 8 weeks daily transcranial PEMF treatment (T-PEMF) of persons with PD on rest and postural hand tremor characteristics and on inter-hand coherence.

METHODS

Hand accelerations of 50 PD participants with uni- or bilateral tremor participating in a clinical trial were analysed. A rest and postural tremor task performed during serial subtraction was assessed before and after 8 weeks of T-PEMF (30 min/day, 50 Hz, ±50 V, 3 ms squared pulses) or placebo treatment (sham stimulation 30 min/day). Forty matched healthy persons (no treatment) were included as reference. Intensity and inter-hand coherence related measures were extracted.

RESULTS

The T-PEMF treatment decreased the inter-hand coherence in the PD group with unilateral postural tremor. The PD group with unilateral postural tremor was less clinically affected by the disease than the PD group with bilateral postural tremor. However, no differences between T-PEMF and placebo treatment on either intensity related or coherence related measures were found when all persons with PD were included in the analyses. The peak power decreased and the tremor intensity tended to decrease in both treatment groups.

CONCLUSIONS

Eight weeks of T-PEMF treatment decreased inter-hand coherence in the PD group with unilateral postural tremor, while no effects of T-PEMF treatment were found for the entire PD group. The unilateral postural tremor group was less clinically affected than the bilateral postural tremor group, suggesting that early treatment initiation may be beneficial. In theory, a reduced inter-hand coherence could result from a neuronal treatment response increasing inter-hemispheric inhibition. However, this requires further studies to determine. Studies of even longer treatment periods would be of interest.

TRIAL REGISTRATION

ClinicalTrials.gov , NCT02125032. Registered 29 April 2014, https://clinicaltrials.gov/ct2/show/NCT02125032?term=NCT02125032&rank=1.

Stress Management Training (SMT) Improves Coping of Tremor-Boosting Psychosocial Stressors and Depression in Patients with Parkinson's Disease: A Controlled Prospective Study

Background

Stress reduction and relaxation exercises are therapeutically suggested to patients with Parkinson's disease (PD) and tremor, but data regarding efficacy or preferential methods are missing.

Objective

To investigate the effect of a standardized stress management training (SMT) according to Kaluza on coping with tremor-boosting psychosocial stress factors.

Methods

8-week SMT was applied to 82 PD patients with tremor and 30 controls. Changes in stress-associated factors were measured applying four scales: Kaluza's “warning signs for stress” and “stress-amplifying thoughts” and Beck Depression Inventory (BDI) and quality of life (PDQ-8). Short-term outcome (8 weeks) was evaluated in both groups, and long-term outcome (3–6 months) was evaluated only in PD patients.

Results

At baseline, PDQ-8 was worse in PD patients compared to controls. PD patients improved significantly regarding short- and long-term outcome scores of “warning signs for stress,” “stress-amplifying thoughts,” and BDI scores, independently of disease severity or duration. Younger and male PD patients showed the best benefit. Controls improved comparably to PD patients but significantly only with respect to “stress-amplifying thoughts.” Retrospectively, 88% (29/33) of PD patients were rated SMT as helpful 12–18 months later. Self-practicing SMT exercises correlated significantly with subjectively better coping with tremor-related daily impairment and subjective short-term and long-term tremor reduction.

Conclusion

SMT should be a part of therapy of PD patients with tremor.

Deep Brain Stimulation and L-DOPA Therapy: Concepts of Action and Clinical Applications in Parkinson's Disease

L-DOPA is still the most effective pharmacological therapy for the treatment of motor symptoms in Parkinson's disease (PD) almost four decades after it was first used. Deep brain stimulation (DBS) is a safe and highly effective treatment option in patients with PD. Even though a clear understanding of the mechanisms of both treatment methods is yet to be obtained, the combination of both treatments is the most effective standard evidenced-based therapy to date. Recent studies have demonstrated that DBS is a therapy option even in the early course of the disease, when first complications arise despite a rigorous adjustment of the pharmacological treatment. The unique feature of this therapeutic approach is the ability to preferentially modulate specific brain networks through the choice of stimulation site. The clinical effects have been unequivocally confirmed in recent studies; however, the impact of DBS and the supplementary effect of L-DOPA on the neuronal network are not yet fully understood. In this review, we present emerging data on the presumable mechanisms of DBS in patients with PD and discuss the pathophysiological similarities and differences in the effects of DBS in comparison to dopaminergic medication. Targeted, selective modulation of brain networks by DBS and pharmacodynamic effects of L-DOPA therapy on the central nervous system are presented. Moreover, we outline the perioperative algorithms for PD patients before and directly after the implantation of DBS electrodes and strategies for the reduction of side effects and optimization of motor and non-motor symptoms.

Impact of Tremor on Patients With Early Stage Parkinson's Disease

Tremor is one of the most visible features of Parkinson's disease (PD), and the majority of PD patients experience tremor during the course of the disease. However, the distress caused by this cardinal motor feature for patients early in the course of their PD is commonly underappreciated. People living with early stage PD often experience intense embarrassment and difficulties due to their tremor that limit social interactions, and tremor frequently interferes with the ability to perform activities of daily living and simple tasks at home and work. Although tremor is primarily managed with medications, both tremor response and satisfaction with medical therapy are highly variable. This review offers an overview of reports of the patient experience of tremor in early stage PD and current management options for this cardinal motor feature.